Romania notified the European Commission in July of its intention to grant a 135 million euro ($197.6 million) debt-to-equity swap and a 339.2 million euro state guarantee for Oltchim."The Commission must verify whether the measures planned for Oltchim would entail state aid, and if so whether such measures would not give rise to excessive distortions of competition," Competition Commissioner Neelie Kroes said in a statement.

The EU competition watchdog did not specify a timeframe for its investigation.Oltchim, which plans to buy the petrochemical assets owned by the country's biggest oil firm, Petrom, faces financing problems amid falling demand for its products.